Telephone-key.



G. E. MUELLER; TELEFHOHE KEY.

APPLICATION FILED MAR. 1, 1902.

l m E 6 j PS Am J m M m M 5 Km hw i .w a

f 5B6 u E m c v Patented Apr. 6, 1915.

2 SHEETS-SHEET 2.

ami g? G EORGE E. MUELLER, OF AURORA, ILLINOIS, ASSIGNOR, BY IVIES'NE ASSIGNMENTS, TO

KIEIIJLOGG SWITCHBOARD &

SUPPLY COMPANY,

A CORPORATION OF ILLINOIS.

TELEPHONEKEY.

Specification of Letters Patent.

Application filed March 1, 1907. Serial No. 360,116.

To all I i/1011i it may concern lie it known that I, GEORGE E. Mnnnnnn,

.a citizen of the United States, residing at more particularly with that type which is used in connecting the operators telephone set in circuit and applying ringing current to the line for signaling substations 'and especially for signaling one ofa number of substations on the line. I

The principal object of the present invention is to provide a key of the character in dicated having certain features of construction including novel catch mechanism for maintaining the various actuating members in. their dilferent operating positions, together with a vnovel arrangement of parts which enable the key to be economically manufactured, while leaving it compact and simple in construction and eiiicicnt in operation.

In the present application, the invention is illustrated in two forms. In each of these a plurality of ringing-keys of the plunger type is shown in association with a listening-key of the lever type, all mounted com-, partly upon an elongated frame. In each of these forms, each longitudinally movable key has three operating positions, a normal, a fully depressed, and an intermediate position. in one form, the fully depressed position is a ringing position and the intermediate position is an indicating position. In the other form, the fully depressed position is a busy position and the intermediate position is a ringing position. In both of these, the catch mechanism, which cooperate-swith these keys in holding them in their different operating posit-ions, includes two pivotally- ETlOllIltGCl catch-bars which extend lengthwise of'the frame along opposite sides 'of the row of keys and are provided with catches which engage corresponding catch projections on the said keys. Electromagnets having ranmature mechanism cooperating with said catch-bars are provided for operating the catch-bars in accordance with predetermined circuit conditions brought,

refer to like parts.

about by specific acts performed whileflestablishing a conversational circuitbetween two subscribers.

The invention also includes other features and details which together with theaboite, will be more fully understood upon reference to the following detailed description taken in connection with the accompanying drawing, and the scope of the invention will be articularly pointed out in the appended claims.

Referring to said drawings, Figures 1' to T inclusive illustrate a combined ringing and listening key constituting one form of the invention, while Flgs. S to 15 inclusive illus trate a similar combined ringing and listening key constituting a second form. Fig. l is a side elevation of the key constituting the first form; Fig. 9. is an elevation of the same, viewed from the left; Fig. 3 is a similar elevation viewed from the right; Figs. 4;, 5 and G are sectional views indicating different operating positions of a ringing key,

Patented Apr. 6, 1915.

Fig. 5 being taken on a plane indicated by the line of Fig. 1.; and Fig. 7 is a'diagram of circuits illustrating one use for the key; Figs. 8, 9 and 10 are views, similar to Figs. 1, 2 and 3, of the key constituting the sec ond form of the invention; Figs. 11 and 1-2 are details of certain cooperating parts of this key; Figs. 1.3 and ll are sectional views illustrating different positions of a ringing key; and Fig. 15 is .a diagram of circuits illustrating one application of said key.

'1 iroughout these Yl-.;, like characters Referring first to th key illustrated by Figs. 1 to 7 inclusive, idesignates the main supporting frame which consists of a plate having a short horizontal flange 10 upon which a faceplate B is mounted. The faceplate and flange are provided with suitable openings through which the listening-key lever ys K-K -K?K extend downwardly into a position to engage the upwardly extending sets of contact springs S'- S -'-S S respectively? These springs are secured at their lower-ends by a suitable insulating,

member. G preferably secured to the frameplate A by screws 11 and arranged .so as to properly space the springs of each set of contacts. inthe manner illustrated. The

member C is provided with suitable guid- 1 L and each of a pluralit f n K -K* extend. The "keys.

ioo

ing openings through which the lower ends of the keys K K"K, K are adapted to pass. The guiding ends of these keys are reduced in diameter and each is provided with a coiled. returning spring 12 lying in close proximity to it and bearing at its opposite ends against the member anda oulder on the corresponding key. Each of the keys KK I. K 1s adaptedto occupy three operating positions referred toas normal, indicating,

and ringing positions.

In the normal position, a collar 13 on the shank of each key rests against the under face ofwthe flange of the plate A; and the tips of the spring-contacts Hl5, which co operate with the adjacent spring-contacts 16-47, rest against the lnsuiating portion 18 of the key and "out of engagement with catches 20 and 21 011 acts upon a set of springs 5 each other. As the keyis moved downward, the spring-contacts 14 and 15 are moved into engagement with the associated spring-contacts i6 and 17 respectively, by the wedging action of the upper part of the insulating portion 18. 'lfiachkey is also provided gaging-projection which cooperates with the 23 respectively. These bars are pivoted at their opposite ends adjacent to the under side of the flange'l'O, the bar 22 being pivoted to the posts 25, and the bar 23 to similar posts 24. The bar 23 is provided at one end with a downward projection 26 which mounted upon, and insulated from, theframe plateA at a point adjacent to the end of the insulating member 0. This set includes the movable contact-springs 2728'29, which cooperate I I respectively with the springs 30-31-32,'

the s'prings'27, 28 and 29 being united at their-upper ends by the insulating piece-33. These springs, in acting upon the projection 26, tend to maintain the bars 22 and 23 in the position illustrated in Fig. 4-that is, with the catch 20 in engaging position and the catch--21 out of engaging position. The movementofthe bar 22 is communicated to the bar 23 through a connecting link 3 1extending between the bars adjacent to the '50 set jof contact-springs S Normally, when a key is depressed, the inclined portion of its collar 19 presses against the cooperating catch 20 and rocksthe bars 22 and 23 about their pivots, thereby moving all catches 20 out of engaging position and releasing any previously engaged key. As the collar 19 on the depressed key passes I latter, springs into engaging position and tho key isheld thereby thls position upon the energization of a71- electromagnet E which is secured to the fl frame-plate'A between a projecting flange v 1n its r nging position. It is intended that the key be released from 85 anda pole-piece 36. This electromagnet is arrangedin line with the sets of spring about their pivots to the w th a collar l9'forming a catch-err A the catch-bars 22 and the catch 20, the

contacts S ""S" and-- in compact relation with the other partsof the key strueture. The electromagnet actuates armature '37 which is pivoted at the'lower end of'the tion. Upon the retraction ofthe armature,

however, the key is restpred by-its spring'to its normal position.

As previously indicated, the key'structure remains attracted, the key thus engaged is held in this 'posi-- position is'reached, w1ll at once return includes the listening-key lever L which is pivoted at the point 40 to the frame-plate and is provided with'a projection having an insulated covering d1 which cooperates the present instance, 42-43 are bound together at their upper ends by,..an insulating fpiece {i4 and are moved against their spring tenisioninto engagementwith the cofiperating spring-con'- The s ring-'contacts 42-,4315 46 are secure at their tacts 15'46 respectively.

lower ends to the lower edge of the frameplate A by means of a suitable insulating with a set of listening-key contacts S. In

the. spring contacts member, 47 arranged in line'with the bar 0 and at the opposite end of-the frame from the set of spring. contacts S The listeningkey lever L. is adaptedto' be retained in its actuated position by the engagement of.

a yielding catch l8, carried by the lever, with a catch 49 carried by the catch-bar 22. As

the lever L is thrown to the right in Fig. 1,

the catch 48, shown clearly in Fig. 5, is car-; ried downward and its inclined face engages 4:8- is that of the catch 19, and the'catch moved against the tension of its supporting spring 50 until it has 49. The upper face of the catch 48 then en-i gages the lower face of the catch 49; and the listening-key lever tuated position until such time as thecatch= bar 22 is rocked. 'As' previou this will occur upon the attraction of the' armature 37 ,of electromagnet-:E,.-'or;upon

the depression of a 'ringingikey ,=.K

purpose of manually rock-{. ing the catch-bars 22 and 23, the catch bar opening inthef' posi" or K. For the 221s provided withlan upward extension :51- extending-through a'suitable ange 10 and the face-plateB into a tion to be readily actuated by the thumb or. finger at the will of the-operator. i;

In the diagram of Fig. 7,11, have illus passedby the catch 2 is retained in, its ac sly indicated,

trated a cord-circuit in which the combined ringing and listening-key above described may be employed. This diagram illustrates two telephone lines L-L extending from substations DD to the central oilice where they are provided with suitable jacks J which are adapted to be connected by a link-circuit L including the talking strands nection is desired with the line L.

52*53 uniting the tip and sleeve contacts of the plugs l and P and divided into sections by interposed condensers The answering end of the link-circuit L is provided with a tip supervisory relay 56 and a sleeve supervisory relay 57 which control the supervisory lamp .58. TheYcalling end of the link-circuit is provided likewise with a tip supervisory relay. 59 and a sleeve supervisory relay 60 which cooperate with other relays and apparatus which will best be understood by outlining the operation of the system. Assuming that a party at substation D has been answered by the operator, and the operator'has learned that conlhe previous insertion of the answering plug P into the jack J of the called line will have connected the line limbs to the strands 52-53 of the link-circuit and, by energizing both supervisory relays 56 and 57, will have prevented the display of the supervisory lamp As soon as the operator threw over her listening-key lever L to place her telephone set S in circuit with the calling party, she

closed contacts 42%?) and 43'l6 and, by

reason of the catcheslS-dl), these contacts are held closed as long as the catch-bar 22 remains in its normal position. After learning the number oft-he called-for party, the operator will insert the plug P into the ack of the line L and depress the appropriate ringing-key K, K K or K*. In the diagram, i"S S -S*, controlled by these keys, are shown separated. s

A ssuming that the line L is idle at the time the plug P is inserted into the jack of said line, then current will flow from the intermediate tap of the battery B which may, for example, supply'current at a pressure of eight volts, through the polarized relay 61, normal contact 62 of sleeve super visory relay 60, contact 63-64 of the relay 65, plug and jack sleeve contacts and'the winding of-cut-ofi relay 66 to ground. The directionof thiscurrent flow is such as to move the armature 67 of the polarized relay 61 to the left into engagement with contact 68, thereby completing 'a circuit for the sleeve supervisory relay from the live pole of the battery B, which may supply current at a pressure 10f, say, twenty-four volts, through the winding of the relay 60 and contact (ES-67 to ground, thus energizing said relay to. move its contact 62 to its alternate position and thereby interrup the enthe contacts ofeach of the sets er izin circuit for the olarized relatil- 7: b i

and complete a new path for current through the winding of supervisory relay 60 which, may be traced alternate contact 62, closed contact plug and jack sleeve contacts and cut-off. relay 66 to ground. The energizatioirof, relay 0 also closed its contacts 69, TOand 71. By the closing of contact 71, a path-is completed through supervisory lamp which extends from the live pole of the but; tery B through said lamp, the normal c011 tact 73 of tip supervisory relay 59 and closed contact 71'to ground, thereby causing the illumination of said lamp. The closing of contact 69 completes a path for current from the live pole of the battery through said closed contact and through the winding of the so-called tlip fiop relay 74 to the con.- tacts 17 of the ringing-keys. lhe closing contact likewise completes a path from fromsaid winding, through l throughclosed contact 70, closed contact 1'6 of relay 65 to the tip of the calling plugfP r \Vith the parts in this condition, the'operator will then depress the proper ringing key to actuate the call signal at substation D Preferably, selective signaling is-en ti'on of ringingcurrent to the line fronrgenerat-ors G, G G and G in the present instance shown connected between ground and the contacts 14 or each of the sets of spring contactsS, S S and S. Assuming that i the key K is depressed for the purpose of supplying ringing current to actuate the call signal, at substation depression of D then upon the full the key the contacts 14%16 and 1517 of the set S will be engaged'respectively, and the key will be held in this position by. the engagement of thecatch 20 with the collar 19 in the manner illustrated in Fig. 4. This depression of the key K will rock the catch-bars suiiiciently to dis engage catches i849 and thereby free'il-isteningv lever L to allow it to return, m normal. The contacts 15 are connectedto ground through an interrupter I so that as soon ascontacts l5--17 of key K are moved $1 into engagement, circuit 'is completed through the flip-flop relay 74 and'the interrupter I to ground.- As'the interrupter rotates, .the relay 7el'will be successively energized and de'cfnergizcd to move its contact I, 3

75. When this contact is in its alternate position, current will be supplied, from the generator (P through the contacts 14-16 of key K, alternate contact 7;), closed contact 3 70, closed contact 7 6, plug and jack tip 0511- f tacts, thence to the tip limb of the line (the cut-off relay 66 having been energized. to

interrupt the. normal line connections and to connect the line limbs'with the contactsof the jack J through the substation, back over the sleeve limb and through the windhook,

called-for party responds.' As soon as he.

does this by removing his receiver from its through the sleevesupervisory' relay 60 to the winding of'the cut-ofl re1ay'66 as before, thence by one paththrough said winding to ground, andby another. over the sleeve limb.

- of the line, through the substation, back over and jack tip contacts,

Y and-firo movement's, and'the Winding supervisory relay '59 to ground. ing of'this circuit cuitfis battery 13' will, as man's. a .n

the tip limb of the line, through the plug closed contacts 76, closed'contact 70, and normal contact 75, as soonas it assumes this position in its toof tip T will energize supervisory relay 5.9 and, by 'moving'its contact 7 3 to its alternate position, interrupt the circuit through the supervisorylamp 72 to cause its extinguishment through: 'el'ectromag'net E which controls the movement of r the catch-bar's 22-23 of the ringing and listening key. This circompleted from the livepole of the through the winding of said electromagnet, alternate contact 73 of tip supervisory-,relay 59', and closed contact 71 of sleeve'supervi'sory relay, to ground. As soon as electromagnet E is energized, its armature 37 is bars 22-23 are rocked to the position illustrated in Fig. 6, whereupon the actuated free to return, under the force key K is of its spring 12, to its'indicating position;

As illustrated in said figure, when in thisengages the collar 19;

position, the catch' 21 and if at any time it becomes necessary to again signal the party at substation D the operator canjreadily see that key K was last depressed, "since no. other keys will 0c cu'py this1 interinediate position 'at this time.

The movement-10f thefcatch-bar 22, as 'a re-.

suit of therfener zation' of electromagnet E,

" countess-3'1aides-3250f this set will complete the talkingicircuit through the link-circuit strands; end-the engagement of contacts 27 -,30 will provide a ne path for current through;the= electromagnet E by Way of saidcontacts' andithe closed contact 71 of supervisory." relayffflOlto ground. At

the end'of' conyersat-ion',-' the" parties restore .and 72in the usual *mannernas asignal to s soon as she' removes the plug P from a path for battery. current is completed e clos- Again, is in the position-illustrated m Fig. 6, the

and .close a circuitv tlon.

attracted and the catchcientlv above that of the plug, current will fio v'from.the

icated, operate the set The engagement of tery B and 'mal to its alternate the operator to take down the connection.

the jack J ofthe line L, whileperforming this operation, the previous circuit through v the sleeve superviscr yreiay 60 and the cutoff relay $36 .will be interrupted with a consequent interruption of the circuit through 'electromagnet E at contact71 of said supervisory relay. vAs soon as this magnet is deenergized, its armature 37 will be retracted byits spring 38; and by reason of the disengagement of catch 21 with the collar 19 of key K, said key Will return, under the action of its spring, to its normal position. In theoperation of the key mechanism, only one key K, K K or K Will be depressed at one time. Thus if key K issdepressed While key Kt is in its fully depressed about its pivot by the engagement ofthe inclined face of the collar 19 on key K? with the associated catch 20; and consequently the catch 20,"engaging the collar 19 of depressed key- K, will be disengaged and. the latter key will return to its normal positlon.

if-keyK be depressed While key K catch-bar 23. will be similarly rocked through the'similar engagement of collar19. of key K -with the associated catch 21, and the catch 21 of key K will be disengaged and. saidkeywill be restored to its normal posl- '95 Assuming that the line into which the plug. P has been inserted is busy, then there Will exist at the sleeve contacts ofthe jacks of the line'L a potential resulting from'the connection of the sleeve contact of one of said jacks with the live pole: of the i battery B either by way of the sleeve super; visory relay 57 and the answering plug-"15 or the supervisory relay 60 and'theffsleeve contact of the calling plug P of another.

This potential will be. sufliof the intermediatetap so that, upon the insertion .11 sleeve' contact of the jack through the sleeve] contact of the plug 1, closed contact (SA-63,1 I i 7 normal contact'62 of supervisory relay'60, and polarized relay 61 to the intermediatetapofthe battery B. This current-flow will result in actuatin the polarized; relay. 61to move its contact 6% to the rightinto e11 1 g gageinent with contact 77, therebycomplet- :1- ing a circuitfrom the live pole of the bat.

through the lower winding 'of-rela'y closed ,contacts 77-67 to ground.'- v The closing of this circuit will energize relay 65 to open its normally closed'co ntact 7 6, if;

link-circuit.

of the battery B close conti'cts78-64,followed bythe-oplen ingaof contacts 63-61,

close contacts-.79 and 80, and moves contact 81 fromits norof contact '63-'64 interrupts the path for: current through the polarized relay 61; but

since this interruption occurs after'the dos- 130 position. The opening.

ward movement' of the key, it is carried over .the left face of the inclined portion 107 until it- 'reaches the lower end of the'I-shaped slot. During this downward movement, the

spring contact is forcibly moved against its spring tension from its normal position; and'as soon as the end of the tongue 105 reaches the lower end of the slot, the spring.

contact 10-1 returns, under its own tension, to its normal position and thereby moves to the leftof the tongue 105. Upon the return movement of the key and the tongue 105, the broad end of the tongue engages the right-hand face of the inclined portion 10'; and forces the spring contact'104 to the left into engagement with its associated contact 103. This engagement continues until the'key reaches its normal position, at which time the broad end of the tongue 105 again 106 and the spring contact 104; is free. to return, and I mal positi end of the 102, each key is providedwith a collar 103 pivoted at its opposite ends to the posts 113 The catch=bar 112 reaches the upper end of the I-shaped slot r its spring tension, 'to its norn, thereby again bringing the tongue to the left/of the spring contact In addition to the collar forming a second ca'tch-engaging-projection having a lower inclined surface. This 'co1-,

lar cooperates with-the catches 109-110 of the catch-bars 111-112. The bar 111 is extending outwardly from the frame-plate tr near the under side of the flange b. This the posts 113 'is on aline intermediate of the catches 109 at its pivotal connection with lower side, and the catches 114-.at its upper side. The'latter catches cooperate with the collars .102 of the ke normal positions,

s to look them in their as illustrated in Fig. 9. on the other hand is pivoted near its upper end to the posts 115 which project. downwardl' from the flange b. The catch-bars 111 and 112 in this case are independently controlled by electroina nets e-e', which are mounted side-by si e upon aflange 116extending outwardly from v the" lower edge of the frame-plate a. Each 4 ing' spring 121 and with an upwardly proarmature armature 117, electromagnet a, .as to move catches 114 out of engaging p0siof these electromagnets is provided with an pivoted at its lower end'and-extending upwardly into operative relation with the associated catch-bar. The armature 117 ofelectromagnet e isprovided with a restoring spring 118 and an upwardly projecting member ll9. which extends through a. suitable aperture in a projection of catchbar 111. Similarly, the armature 120 of electromagnet e is provided with a restorz jecting member 122 which similarly extends through an aperture in a-projection of the catch bar 112. Thus the attraction of the due to the energization of rocks the catch-bar lll's'o tionand thereby unlock' the rmgmg-keys 'tion provided the provided the armature net e is attracted at such position, the appropriate catch 109 engages It will' be apparent by free any keywhich v pressed position, The set of on means of a re'ciprof 5 carriesi at'oneenda opening 137 in eration of theringing-keys [if-=7 depressed to its trated in Fig. 14,

gized, since at such catch 110 of the catch-bar 112 will be ina Upon the subsequent retraction termediate position, a's'i the same collar 108. from the arrangement of the catches. 109-? 110, relative to'the collar .108, thatthe deQ' v v pression of any -"one key will forceall the catches out of engaging positionand-theretacts 8 is operatedby eating bar 123 which projection 124 which .is

adapted toien'gage an insulatinginember 125 toactuate (31166011 is at the tinie'in ads- The' key, beingftliereulon lowest position, as'-' uswill be held in such'posijj j electromagnet eis ener-y time the appropriate.

tacts springs 126 and l27, -the"former'to'em gage contact 128, and thef-latter to disenage contact129 and engage .oontact'130. he reciprocating bar 123is-hnng 131'and 132', plate a adjacent to ciprocating' bar 123 corresponding "to-each ringlngekeyyiwhich has an inclined edge with which a adapted to engage to cause the'reciprocm '1 depreesion of the key. In each case, the finger 134 is guided- 134, carried by the corresponding hey, is tion of the bar upon th by a slot 135 in the frame-plate a, through which thesaid finger passes. From this-it y ink' pivotally secured to thefraineits flange 6 The re--' carries a projection 133.

1.0.5. "will be apparent that upon the depression; i i

of any one of the'ringing-keyslk' k 4 th eiprocatlngbar 123I be P" I 110 erated to actuate the contacts of set .9,

The, listening key lever L. is pivoted at 136 to a project on extending from the face of the frame-plate a through a suitablethe catch-bar 111. TheIlis5 tening-key lever is provided with'a suitable projection having an.insulated covering 138 which is adapted to actuatethe springs 139 and 140 of the set of spring contacts, 8 to engage theircoiiperating springs. 141 and a 142, respectively. This'movement is acconiplished by throwing the lever-L to the right in Fig. 8L In this-form ofthe invention, thelistening-key is independent in its'op- 2 3;k4 Referring L extending-from substationsM and N to central oliice provided with a suitable-linkcircuit L for" uniting the lines for conversation, it will be-seen that the line circuits are substantially the same as those shown nowto the diagram'fof Figh -'15, Wl1lCl1 illustrates ,two,subscribers lines l1-" 1 in Fig. 7 and that the link-circuit is of the tour-relay type, including supervisory reaysgl-li-l lli associated with the answering endot' the linlocircuit, and similar superiiis0ry relays HIP-146 associated with the calling end of said circuit, the relays 113- f 1.1M;controlling supervisory lamp 1&7, and f lays' 1-i51' 1(3 controlling supervisory lamp 1-18. Assuming that a party at sub- ;uj station M has removed his receiver, the 'operator will respond by inserting the answering plug P into a jack ot' the line L and will place her operators set 5 in circuit by depressing her listening-key lever L to circuit through substation M and back over the tip side of the circuit'to ground through opening of the latter contact interrupts a possible connection for ringing current to 'the tip contact of the plug 1. The closing of contact sendsja. busy signal over the line'to the calling party. This signal 70 may' be transmitted through the agency of an interrupter iand an induction coil' 157, the interrupter being included in a primary circuit with the primary winding of the induction coil and with the battery 1); and the 75 secondary circuit including a secondary ,u'indinn' of said induction coil.'condenser 158, closed contactlBi, the sleeve side of the lfijclose contacts l3 9-1l1 and 1410-4-12, Hav- Ting learned the desired substation to be, for the various ground connections with the tip ample b t ti N line L, she will strandjot the link-circuit L". The closing the n- Plug P i t a j k f otcontact 135 of relay 153 completes a cirh li L d depress a i i k k, If, cult to ground through the winding of elecfk ork" to cause the operation of the call tro uagnet c which controls catch-bar 112. 35

"I sig'nal at substation N. The insertion of the- The attraction of armature 120, resulting .j-plug into the jack will complete a circuit from the encrgization of electromagnet e, from h li pole of battery 6 through the brings the catches 110 into engaging posiryujw'vihding of sleeve supervisory lay 1&6, tion, and the key .i.:* is thereby held in its dosed Contacts 7- ping d j k tully depressed position. Upon learning 99 'jsl eeve contacts and the winding of cut-ofi the busy condition of the line, as before, the V felay VH9 to grmmd. The closing f thi operator will take down the connection,

l circuit will energize the sleeve supervisory i f theelwtmnmgnets'e and will jimmy 5 d, the p fi relay ltgflgh he deenergizedmnd through the action of the -fdr w @1086 it Contact 150 t cause th returning spring 101, the key it" will be reillumination of lamp M8, and the latter to Stored t0 its normal POSitiOD- I fi w'ruPh the normal line connection and 111 64159 the Called linevv is e, t he time extend the line limbs to the tip and sleeve the plug 3 is inserted into its jack, there contacts of the jacks. As soon as contact W111 b 110 Current flOW through relay 3, closed) a circuit will l b l t d and consequently electromagnet e will not :through the winding of electroniagnet e by he energized andcatch-bar 112 ivill not be which catch-bar 111 is controlled. This ciractuated to hold the key in'its fully del icuit extends from the live pole of the battery pressed position. At th'is time, however, the Z) through the winding of said electromagcatches'109 ofcatch-har 111'will be in their netyclosecl contacts lot-r152 and closed con engaging position, and the key If will not be 'tact'lSO to ground. The resulting cnergizatree-to return to its normal position, but will 'tion or electromagnet c rocks the catch-bar 11150 as to unlock the ringing-keys 15- a L 11*. Until this occurs, the operator canfci'intact 0F the jack over the sleeve side of the lllllli-l'lltllll. through Conlu('fi,l" -Z(i--l28 and the Winding of relay 153 to ground. thereby energizing said relay to close its contacts 5 and to open its contact'ififi. :The'

stop at its intermediate or ringing position. Upon this return movement, as was previously pointed out, the associated conround, from the live pole of battery 5, through the winding of supervisory relay 14G contact 127-126 plug and ]uck sleeve contacts to theu'i'nding ot' cut-oil relay Ill); thence by one path through theunidingof no't depress the proper ringing key. As-- tact-s 103-10:l of key It" are brought into 110 inning that the operator depresses key if engagement. with the result of an intermit to actuate the call signal at substation N, it tent application of ringing current from the ivi'llbe seen that the ringing circuit will not generator through the interrupter c v e completed upon the t'ull depression of the one Winding of relay 159 and closed contacts" fey. since the contacts lllii lll tot sucli key 160161 to the tip contact of the plug P 'ljj'hi'enot closcdhy this movement; but on the and thence over the line L and to ground other hand, the spring contact of the set 3 through the cubotl relay 149. The flow of I 'ivill be operated by the movement of recipro ringing current over this circuit will be of eating bar 123 to break contact 127-129 such :1 ch: racter as not to cause the relay and close contact l27--13()faud at the same 159 to attract its contacts: but as soon as 129 ,lt lllit to close contact 1213-428. It the line the called-tor party respoiuls and thereby "lf'is busy at this tiuux a potential above that completes a path tor battery current 'ot1qround Will exist at the sleeve contact of through the substation. current ivill flouyas the jacks j "and. upon the closing of contactsoon as the interrupter 0* establishes conj1 2l3l2o', current ivill llou' from the sleeve nection between contact ill l of key is" and 151-152 breaks the circuit 20. closed "contact-150 to ".Aof; contact 160-7161 interrupts the connec said relay to ground, and by another over the'line'through the substation and back---" through the plug and jack tip contacts,

closed contact 156, closed contact; 161 -160;

the right-hand winding of relay 159, contact 104103' through the interrupter c to ground. The completion of this circuit will energize relay 159 to close c9ntacts'162.152,- followed by the opening of contacts 151-'l52; and the closing of contact 161-163, followed by the opening of con tacts 160161. The 'openin of contact 7 electromagnet 6 and thereby. releases key In from its ringing position. and --allo'ws it to return to normal. The engagement-of contacts 152-462 completes a locking circuit for the relay. 1'59 extending from the live pole of battery 6 through the left-hand winding of said" relay, closed contacts 152- -162 and ground. Theopem'ng -j tion to the ringingkeys, and the closing of contact 161-463 completes: the a talking strand at this point. Thus it will be seen 'that in the'.operation of the system, the

.ri-ngmgkeycan not be depressed untilthe calling plug hasbeen inserted into'the jack I j Then, when depressed, if the line.is busy, it I 80.. I and a busy signal is transmitted to the callis retained in its fully depressed position ing party. However, if the" line is not busy,

the key is allowed to return 'to itsintermediate or ringing position-and it remains in this position until the called-for party responds, whereupon; it .is freed and allowed. to return to its normal position. With the parties connected, the supervisory lamps 1 1.7-14 8 remain.dark; by reason otthe en: ergization of tip 1 supervisory relays- 143 andj.145; but at the'close of conversa tion, the restorations of I the receivers to their hooks at the substations interrupts the flow of current to these supervisory relays; and .upon the return of their contacts to normal, the said lanips are lightedas a signal to the operator to take' down the connection. a

It should be, understood tliat the specific key construction may be modified consider I ably without departing from the spirit and scope of my invention, and that in the practice of the same, the, electromagnets by 'whi'ch the latch mechanism is controlled might be variously con-negated in existing or novel circuit. arrangements. The I accompanying diagrams are intended to be merely typical and to illustrate completely an application of each form of the invention. What I claim as new and desire to secure by. LettersPatent of the United States is -1. .A telephone key-comprisinga supporting frame, suitable contacts carried thereby,

a spring returnedactuating member for said j contacts having three operating positions,

ing frame,

her for said contacts having means for holding said member initssecond I and third I positions noved thereto,

and means for operating said hiiding means.; H

.2- A telephone key comprising a" support" ing .irame, suitable contacts cariidiherej said contacts'having three operating posi- 7 Moms, means ,for holding said member in its second'andthirdpositions when moved I thereto, and

.electro magnetically means for operating said holding means.

3.' A telephone key comprisinga support suitable contacts carried thereby, f 'a spring returned actuating inember'for said contacts having three operating posiing frame,

tions, and .electromagnetically. actuated-T catches for holding said member-in its sec- 0nd and thirdpositions when moved'thereto.' 4. A'telephone key'comprising' a supportsuitable contacts carried a spring returnedactuating' member for said contacts havingthree .o a pair of catches. :for severallyvholding said member-in two'of' said operatin positions, r .and means for simultaneousl 1 one of saidcat'ches and moving into engaging position-to the'rebyallow. the a movement of said member from oneoperating position to another. V

- 5; A telephone key comprising a supporti -ing'f rame,

suitable contacts carried thereby a spring returned actuating member for said "11- operatin positions, a

contacts having three pair of catches for severally: member in two .of'said and electromagneticall'y I simultaneously disengaging one of said. 7

operating positions,

:catches and moying the other into engaging 7. A telephone ringi k (,ompnisin I p i supporting frame, suitable contacts carried thereby, a. spring returned actuating m emher for said contacts. having a ringing and 120,: i

.two other operating positions, means for l holding said actuating -member in. its ring" mg posltlon when oncemoved thereto, and

- electromagnetically actuated means for subsequently freeing said member andallowing 7 it to assume anotherof itssaid operating positions. i 'f- 8. A telephone ringingkey'comprising :1 supporting frame,

thereby, a springreturned actuating rnem- "130':

crating positions,

by, a spring returned actuating member for 7 7' actuated 5; 9'

thereby, 5)

sengagmgieof the other H oldi-ng'said v actuated meansfor'j Y I one operating posi ion 9 a rlngingan'd ed thereto, and

another; of its 11 suitable contacts carried bcr for said contacts having 'a rin ing and two other operating positions, an electro iuau'nctically artnatcd catch mechanism opcratirc when in onc position to hold said nicmhcr in its ringing position and when in another position to hold said member in anollicr of it's said opcrating positions.

A. tclcplionc ltcy comprising a narrow supporting l'rainc. suitable spring contacts carrii-il ,thcrcby. a longitudinally movable ltcy for opcraiinc said contac' and ha ing a plurality of opcrating positions, projeclions on said ltcy and coiipcrating catches on said t'ranic spacial so as to hold said key in ilili'crt-nl opi ating positions, a controlling rlia-lronmgn t scrurcd to said .lranie and lying substantially in the planc of said con tacts. and an arinalurc actuatcd by said clcclronnrgnri to opcralr said catches.

in. A cuniliincil tclcphonc listening and ringing ltcy comprising a narrow support-- ing l'rainc. suitahlc ringing contacts carricd by said framc. an actuating member for said contacts having a plurality of operatingpositions. catch mechanism for holding said actuating nicnibcr in dili'crent operating positions. a controlling: elcctromagnct serurtal to said frame and lying substantially in thc plant: of said contacts. an armature for said clcrlroinagnet. opcratiriiconnections bctwccn said armature and said catch 'incchanisnn listening contacts lying adjacent to said cleclroma rnct and an actuating nicnilu-r l'or said listening contacts mounted in said framc adjacent to the end of szid elcctroniagiict and in the plane oi said magnet and said listcnino; and ringing contacts.

11. 1; party line telephone ring fl comprising an clongatcd si'ipportjing fiaine, a row oi sctsot spring contacts carried there- 'by. a plu'ality of actuating iiicmbers for said sets of contacts mounted in said frame in a row and each having a plura ity oi operating positions, catch engaging projections on said actuating i'aeinbers, catch-bars extending lengtlii'iise of said frainc in close proximity to said actui t ri hers, catches on said bars touting members in t ing; positions. and n bars to practically :1 hi 'ality of the said catc of the said actuating members,

12. A party line telephone ringinpltcy comprising an clongatcd supporting t ranic. a row of sets of spring, contacts carricd thereby. a plurality of actuating: inrnilafor said frame in a row and cat-h harin a plurality of opcrai'in; positions. catch cnnfaginfi projcctions on said actuating incnihcrs. ratrh bars,cittcnilin lcng thwisc oi' said frame in closc proximity to said actuating: nicinbcrs. catchcson said bars l'or holding said actuating nicnibcrs in ihcir ilill'crcn'i opcratii ioof contacts inouiitcd in said sitions and e'iccti'omamieticall actuated me; 11, for actuating said bars to practically simultaneously operate a plurality of the said catches acting on one of the said actuating" members.

13. A party com prising a row oi bers, catch-bars extending lengthwise of said lramc on opposite sides of and in close i "y to said aitnating members,

for holding said aci '11 g 'n'ibcrs in their tliii'erent operating pi ioi i and means for actuating said bto prac 'i ally simultaneously oper to a pluhe said actuating members.

ii. A party one telephone ringing-key comprising an elongated supporting in ie, a r0? 0t sets ol spring CHTIHCl s contacis thereby, a plurality of actuating member for said sets of contacts nionnted in said frame in a row of operating positions, catcli-engaging-procctions on said actuating members, catch bars extending lengthwise of said frame on opposite sidcs of and in close proximity to said actuating members, catches on said bars for holding said actuating members in their dili'erciit ope'ating positions, and electromagnetic lly actuated means for actuating said to practically sinuili'ianeously operate a plurality of the said catches acting on one of the said actuating members.

A Jarty line telenioiic ringing-key in clong'atcd supporting frame. i upwardly projecting spring hereby, plurality of ting longitudinally 1210K" 15 tt-lcplionc ringing-hey comprising an rhino-ind snpporlin a row it sets of irdly pr jcct in: con'iacis 'ict ncrchy, a pinrali y I n longitudinali} ii'iorii lqcys inounicd in said *lrarne a row in positions to ('(lll tarts respectively ahcn itcprcsscd, springs returning; said keys to their normal positions. catch -engaging-projta-tions on said in said pluand each having a plurality tions,

keys, coiiperating catch-bars extending 1 lengthwise ofsaidframe in close proximity to said keys and having their engaging parts positioned with reference to said projections so as to enable said keys to be held ina plurality of positionsfan electromagnet located adjacent to one end of said frame, an upwardly extending armature operated thereby, and Operative connections between one of said catch-bars and said armature.

17. A party line telephone ringing-key comprising an elongated supporting frame, a row of sets of upwardly projecting spring contacts carried thereby, a plurality of downwardly projecting longitudinally movable actuating keys mounted in said frame in a row in positions to engage said sets of contacts respectively when depressed, springs for returning said keys to their normal positions, catch engaging projections on said keys and cooperating catch bars extending comprising an elongated supporting frame,

a row of sets of upwardly projecting spring contacts carried thereby, a plurality of down- Wardly projecting longitudinally movable actuating keys mounted in said frame in a row in positions to engage said sets of contacts respectively when depressed, springs for returning said keys to their normal positions, catch engaging projections on said keys, cooperating catch bars extending lengthwise of said frame upon opposite sides of and in close proximity to said keys and having their engaging parts positioned with reference to said projections so as to enable said keys to be held in a plurality of posielectromagneltically actuated armature mechanism adjacent to one end of said frame and operative connections betweensaid armature mechanism and said catchbars.

19. A party line telephone ringing-key comprising an elongated supporting frame, a row of sets of spring contacts carried thereby, a plurality of longitudinally movable actuating keys extending through the face plate of said frame and each having a plurality of operating positions, catch, engaging projections on said keys, elongated 'catchbar mechanism pivotallysecured adjacent to said face-plate and laterally movable toward and from said keys, and catches on said bar mechanism for engaging the coiiperating projections on said keys to hold each of said keys in its operating positions.

20. A party line telephone ringing-key comprising an elongated supporting frame,

' release said holding ;movable key for a row of sets of spring contacts carried thereactuating keys extending through the faceplate of said frame and rality of operating positions, catch engaging projections on said keys, a plurality of elongated catch-bars pivotally secured at points adjacent to the face-plate and on opposite each having a pin g by, a plurality of longitudinally movable Y sides of said keys so as to move toward and a from the same, and catches on said bars for. engaging cooperating pro ections on said keys to hold each of said keys in its different operating positions.

21. A comprising an elongated supporting frame,

a rowof sets of spring contacts carried there-' party line telephone ringing-key adjacent to "said face-plate and on opposite sides of said keys, catches on said bars for engaging the cooperating projections on said keys to hold said keys "in their different operating positions, ated armature mechanism mounted at one end of said frame and operatively connected to said catch-bars.

22. A telephone key comprising a set of electromagnetically actu spring contacts, a reciprocating actuating key therefor, a catcli-ba1"mecl1anis1n movable transversely ofsaid key, a plurality of catchproje'ctions on said mechanism cooperating with said keywhereby sa d key may beheld in a plurality electromagnetic means independent of said key foractuating said mechanism. ,4

A telephone key comprising two sets contacts, a lever for operating one of said sets of contacts, biased to return to normal when moved therefrom, a catch for holding said lever in its actuated position and a longitudinally movable key for said other set of contacts operative, when depressed, to

means. A telephone key comprising two sets of contacts, a lever for operating one of said sets of contacts biased to return to normal when movedv therefrom, a longitudinally movable'key for operating said other set of contacts and a catch member operative to i hold said lever in its actuated position and,

to releasesaid lever when said key is subsequently actuated.

A telephone key comprising two sets of contacts,ia lever for operating one of said sets of contacts biased to return to normal when moved therefrom, a' longitudinally operating said other set'of contacts, a catch bar, a catch thereon for en aging said lever when moved to its operating position, and

cooperating pivoted catch- I jecting through said face-plate into operative relation to said other set of contacts, a

rocking catch-bar lying adjacent to said face-plate, a catch on said bar for holding said lever in its operating position and cooperating parts on said key and bar whereby the operation of said key causes a movement of said bar to release said lever.

27. A telephone key comprising a supporting frame, suitable spring contacts carried thereby, an actuating member for said contacts having a plurality of operating positions, a catch member for holding said actuating member in different operating positions, and additional spring contacts actuated by movement of said catch member.

28. A party line telephone ringing key comprising an elongated supporting frame, sets of spring contacts carried thereby, actuating members tacts, each having a plurality of operatingositions, catch bar mechanism extending engthwise of said frame and operatively related to said actuating members for holding them in different operating positions and addition .1 spring contacts actuated by the movement of said catch bar mechanism.

29. A party line telephone ringing key comprising an elongated supporting frame, sets of spring contacts carried thereby, actuating members tacts each having a plurality of operating ositions, catch bar mechanism extending engthwise of said frame and operatively related to said actuating members for holding for said sets of spring 0011- for said sets of spring conthem in diiferent operating positions, and additional spring contacts lying substantially in the plane of said sets of spring contacts, and in a position to be actuated by the movement of said catch bar mechanism.

30. A party line telephone ringing key comprising'an elongated supporting frame, sets of spring contacts carried thereby, actuating members for said sets of spring contacts, each having a plurality of operating positions, a catch bar of said frame and operatively related to said actuating. members,

sets of spring contacts and in a position to be actuated by the movement of .said catch bar, an electromagnet secured to said frame, an armature actuated thereby and operative connections between said armature and said catch bar.

31. A telephone key comprising a supporting frame, suitable; sets of spring contacts carried thereby, an actuating member for each set having a plurality of operating positions, a catch member for holding said actuating members in their different operating positions, and additional spring contacts actuated by movement of said catch member.

32. A telephone key comprising a supporting frame, suitable sets of spring contacts carried thereby, an actuating member for each set having a plurality of operating positions, a catch member for holding said actuating members in their diiferent operating positions, additional spring contacts actuated by movement of said members whereby a member is released when a second member is actuated.

' In witness whereof, I hereunto subscribe my name this 26 day of February, 1907.

GEORGE E. MUELLER.

Witnesses:

L. D. Kannocc, J. G. KnLLoco.

extending lengthwise additional spring con-. .tacts lying substantially in the plane of said 

